Joss Whedon’s fresh and cheeky adaptation of “Much Ado About Nothing” is a minor miracle — the first filmed Shakespeare comedy in decades that’s actually funny.

Shot on a shoestring budget in 12 days at “The Avengers” director’s mansion in Santa Monica with a bunch of TV actors, this unabashed crowd-pleaser is the anthesis of the star-filled but leaden Bard comedies wrought by Whedon’s Marvel teammate Kenneth Branagh (including “Much Ado” in 1993).

Whedon may have moved the action from 16th-century Sicily to 21st-century Southern California and thrown in such modern conveniences as cellphones, but he sticks to Shakespeare’s (edited) text without interpolations. This is no “The Taming of the Shrew” by way of “10 Things I Hate About You” (not that there’s anything wrong with that).

Most of the men are now apparently involved in organized crime — two arrive in handcuffs and limousines at the home of Leonato (Clark Gregg), who is welcoming the suave Don Pedro (Reed Diamond) and his minions for a weekend filled with romantic intrigues and misunderstandings.

Fran Kranz in “Much Ado About Nothing” (AP/Roadside Attractions)

Leonato’s stiletto-tongued niece Beatrice (Amy Acker) claims to be disinterested in men as Benedick (Alexis Denisof), a member of Don Pedro’s entourage, spurns marriage.

But others in the mansion — a nice bit of real-estate porn — who notice the sparks between these two antagonists can’t help but playfully fanning the flames of their confusion with remarks designed to be overheard by the anti-lovers.

The two decide to wed that very weekend — but Don Pedro’s evil brother Don John (Sean Maher) plots to derail the ceremony by planting false evidence of infidelity by the bride.

It’s up to Beatrice and the newly attentive Benedick to put their squabbling aside long enough to clear her kinswoman — despite the worst investigative efforts of the bumbling constable Dogberry (Nathan Fillion) and his hapless deputies.

Whedon makes this complex plot remarkably accessible for contemporary audiences, especially highlighting the play’s very pre-feminist subtext in Beatrice’s exasperation with the men.

Acker, who was in the TV series “Angel’’ — Whedon’s spinoff from “Buffy the Vampire Slayer’’ — really knocks it out of the park as the whip-smart Beatrice, who does not suffer fools gladly.

It helps that she has terrific chemistry with her “Angel” co-star Denisof — and that both of them make their 500-year-old jibes sound like they just thought them up, as well as being gifted physical comedians. (Even the Bard would probably be impressed at Denisof delivering his lines while doing push-ups).

Among the more senior cast members, Gregg is surely the host with the mostest, moving from “The Avengers” to Shakespeare as if to the manor born; and Fillion, the first actor I’ve ever seen underplay Dogberry, is screamingly hilarious.

The impeccably staged festivities — including a masquerade, a pool party, a pair of weddings and a mock funeral— are elegantly photographed in black-and-white by Jay Hunter.

This “Much Ado About Nothing” is an early summer night’s dream. Don’t miss it.